Failures of Local Anesthesia: Dental Perspective

Dent Clin North Am. 2026 Jan;70(1):15-29. doi: 10.1016/j.cden.2025.07.003. Epub 2025 Oct 14.

Abstract

This review discusses the most prevalent factors causing local anesthesia (LA) failures in dentistry, ranging from operator error to systemic conditions. Various pharmacologic, inflammatory, and psychological factors contributing to LA failure have been discussed. Knowledge about updated evidence on anesthetic agents, block techniques, anatomic variations such as bifid canals and accessory innervation, and the role of patient-specific factors, including systemic conditions and anxiety, is also explored. Strategies for prevention of anesthetic failure have also been discussed.

Keywords: Dental anesthesia; Dental blocks; Dental local anesthetic complications; Inferior alveolar nerve block; Local anesthesia errors; Local anesthesia failure; Nerve blocks; Successful local anesthesia.

Publication types

  • Review

MeSH terms

  • Anesthesia, Dental* / adverse effects
  • Anesthesia, Dental* / methods
  • Anesthesia, Local* / adverse effects
  • Anesthesia, Local* / methods
  • Anesthetics, Local / administration & dosage
  • Dental Anxiety / psychology
  • Humans
  • Inflammation / complications
  • Injections / methods
  • Treatment Failure

Substances

  • Anesthetics, Local